A clevis is a load-transmitting device providing an interconnection between a pair of structures having relative movement therebetween in different planes. A clevis generally is U-shaped to define two ends which are perforated or have holes linearly aligned for receiving a clevis pin, for instance. The base of the U-shaped device simply can be a bent form or, quite often, also have a perforation or hole for receiving a pin-like structure generally perpendicular to the clevis pin through the perforated ends.
Although clevises were used many years ago for such applications as at the end of a wagon tongue, clevises today are used in a variety of high technological applications which require high strength, low weight, low heat transfer properties, and electrical non-conductivity of a connection.
By way of example only, devises have been used at the ends of composite tension straps of the type used in cryogenic dewars. For instance, a cryogenic dewar can have hundreds of composite tension straps extending between a vacuum vessel wall and a coil pack wall of the cryogenic dewar. Such devices can be subjected to a cyclic tension loading application for a duration of 30 years or longer in a vacuum and can be exposed from temperatures ranging from cryogenic (1.8K.) to ambient. Metal devises have been used as interfacing/interconnecting devices at the ends of the composite tension straps, and the metal clevises continue to present problems due to the high thermal expansion and high heat transfer properties of metallic structures. In addition to the undesirability of metal devises for thermal considerations, metal devises are counter productive due to their extreme weight, and special fixturing is required for installation.
This invention is directed to providing a strong lightweight composite clevis which circumvents the weight and thermal conductivity problems of metal clevises, and to satisfy a definite need in this technology.